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"""Expression Intrinsics and math functions in TVM.""" # pylint: disable=redefined-builtin from __future__ import absolute_import as _abs from ._ffi.function import register_func as _register_func from . import make as _make from .api import convert, const from .expr import Call as _Call from .schedule import Buffer as _Buffer def _pack_buffer(buf): """Build intrinsics that packs the buffer. """ assert buf.shape shape = _make.Call("handle", "tvm_stack_make_shape", buf.shape, _Call.Intrinsic, None, 0) strides = _make.Call("handle", "tvm_stack_make_shape", buf.strides, _Call.Intrinsic, None, 0) if buf.strides else 0 pack_args = [buf.data, shape, strides, len(buf.shape), const(0, dtype=buf.dtype), buf.elem_offset] return _make.Call("handle", "tvm_stack_make_array", pack_args, _Call.Intrinsic, None, 0) def call_packed(*args): """Build expression by call an external packed function. The argument to packed function can be Expr or Buffer. The argument is the corresponding POD type when Expr is presented. When the argument is Buffer, the corresponding PackedFunc will recieve an TVMArrayHandle whose content is valid during the callback period. If the PackedFunc is a python callback, then the corresponding argument is NDArray. Parameters ---------- args : list of Expr or Buffer. Positional arguments. Returns ------- call : Expr The call expression. See Also -------- tvm.extern : Create tensor with extern function call. """ call_args = [_pack_buffer(x) if isinstance(x, _Buffer) else x for x in args] return _make.Call( "int32", "tvm_call_packed", call_args, _Call.Intrinsic, None, 0) def call_pure_intrin(dtype, func_name, *args): """Build expression by calling a pure intrinsic function. Intrinsics can be overloaded with multiple data types via the intrinsic translation rule. Parameters ---------- dtype : str The data type of the result. func_name: str The intrinsic function name. args : list Positional arguments. Returns ------- call : Expr The call expression. """ args = convert(args) return _make.Call( dtype, func_name, convert(args), _Call.PureIntrinsic, None, 0) def call_intrin(dtype, func_name, *args): """Build expression by calling an intrinsic function. Intrinsics can be overloaded with multiple data types via the intrinsic translation rule. Parameters ---------- dtype : str The data type of the result. func_name: str The intrinsic function name. args : list Positional arguments. Returns ------- call : Expr The call expression. """ args = convert(args) return _make.Call( dtype, func_name, convert(args), _Call.Intrinsic, None, 0) def call_pure_extern(dtype, func_name, *args): """Build expression by calling a pure extern function. Parameters ---------- dtype : str The data type of the result. func_name: str The extern function name. args : list Positional arguments. Returns ------- call : Expr The call expression. """ return _make.Call( dtype, func_name, convert(args), _Call.PureExtern, None, 0) def call_extern(dtype, func_name, *args): """Build expression by calling a extern function. Parameters ---------- dtype : str The data type of the result. func_name: str The extern function name. args : list Positional arguments. Returns ------- call : Expr The call expression. """ return _make.Call( dtype, func_name, convert(args), _Call.Extern, None, 0) def call_llvm_intrin(dtype, name, *args): """Build expression by calling an llvm intrinsic function Parameters ---------- dtype : str The data type of the result. name : str The name of the llvm intrinsic function. args : list Poistional arguments. Returns ------- call : Expr The call expression. """ import tvm llvm_id = tvm.codegen.llvm_lookup_intrinsic_id(name) assert llvm_id != 0, "%s is not an LLVM intrinsic" % name return call_pure_intrin(dtype, 'llvm_intrin', tvm.const(llvm_id, 'uint32'), *args) def exp(x): """Take exponetial of input x. Parameters ---------- x : Expr Input argument. Returns ------- y : Expr The result. """ return call_pure_intrin(x.dtype, "exp", x) def tanh(x): """Take hyperbolic tanh of input x. Parameters ---------- x : Expr Input argument. Returns ------- y : Expr The result. """ return call_pure_intrin(x.dtype, "tanh", x) def sigmoid(x): """Quick function to get sigmoid Parameters ---------- x : Expr Input argument. Returns ------- y : Expr The result. """ return call_pure_intrin(x.dtype, "sigmoid", x) def log(x): """Take log of input x. Parameters ---------- x : Expr Input argument. Returns ------- y : Expr The result. """ return call_pure_intrin(x.dtype, "log", x) def sqrt(x): """Take square root of input x. Parameters ---------- x : Expr Input argument. Returns ------- y : Expr The result. """ return call_pure_intrin(x.dtype, "sqrt", x) def rsqrt(x): """Take reciprocal of square root of input x. Parameters ---------- x : Expr Input argument. Returns ------- y : Expr The result. """ return call_pure_intrin(x.dtype, "rsqrt", x) def floor(x): """Take floor of float input x. Parameters ---------- x : Expr Input argument. Returns ------- y : Expr The result. """ return _make.floor(x) def ceil(x): """Take ceil of float input x. Parameters ---------- x : Expr Input argument. Returns ------- y : Expr The result. """ return _make.ceil(x) def trunc(x): """Get truncated value of the input. The truncated value of the scalar x is the nearest integer i which is closer to zero than x is. Parameters ---------- x : Expr Input argument. Returns ------- y : Expr The result. """ return _make.trunc(x) def abs(x): """Get absolute value of the input element-wise. Parameters ---------- x : Expr Input argument. Returns ------- y : Expr The result. """ return _make.abs(x) def round(x): """Round elements of the array to the nearest integer. Parameters ---------- x : Expr Input argument. Returns ------- y : Expr The result. """ return _make.round(x) def power(x, y): """x power y Parameters ---------- x : Expr Input argument. y : Expr The exponent Returns ------- z : Expr The result. """ return call_pure_intrin(x.dtype, "pow", x, y) def popcount(x): """Count the number of set bits in input x. Parameters ---------- x : Expr Input argument. Returns ------- y : Expr The result. """ return call_pure_intrin(x.dtype, "popcount", x) def fmod(x, y): """Return the remainder of x divided by y with the same sign as x. Parameters ---------- x : Expr Input argument. y : Expr Input argument. Returns ------- z : Expr The result. """ return call_pure_intrin(x.dtype, "fmod", x, y) def if_then_else(cond, t, f): """Conditional selection expression. Parameters ---------- cond : Expr The condition t : Expr The result expression if cond is true. f : Expr The result expression if cond is false. Returns ------- result : Node The result of conditional expression. Note ---- Unlike Select, if_then_else will not execute the branch that does not satisfy the condition. You can use it to guard against out of bound access. Unlike Select, if_then_else cannot be vectorized if some lanes in the vector have different conditions. """ t = convert(t) f = convert(f) cond = convert(cond) if cond.dtype != "bool": raise TypeError("The condition's data type has to be bool") return call_pure_intrin(t.dtype, "tvm_if_then_else", cond, t, f) # Intrinsic rule related code def register_intrin_rule(target, intrin, f=None, override=False): """Register an intrinsic function generation rule. Intrinsic generation rules are callback functions for code generator to get device specific calls. This function simply translates to. :code:`register_func("tvm.intrin.rule.%s.%s" % (target, intrin), f, override)` TVM may already pre-register intrinsic rules in the backend. However, user can use this function to change the intrinsic translation behavior or add new intrinsic rules during runtime. Parameters ---------- target : str The name of codegen target. intrin : str The name of the instrinsic. f : function, optional The function to be registered. override: boolean optional Whether override existing entry. Returns ------- fregister : function Register function if f is not specified. Examples -------- The following code registers exp expansion rule for opencl. .. code-block:: python register_intrin_rule("opencl", "exp", my_exp_rule, override=True) """ return _register_func("tvm.intrin.rule.%s.%s" % (target, intrin), f, override) def _rule_float_suffix(op): """Intrinsic rule: Add float suffix if it is float32. This is an example intrinsic generation rule. Parameters ---------- op : Expr The call expression of original intrinsic. Returns ------- ret : Expr The translated intrinsic rule. Return same op if no translation is possible. See Also -------- register_intrin_rule : The registeration function for intrin rule. """ if op.dtype == "float32": return call_pure_extern(op.dtype, "%sf" % op.name, *op.args) if op.dtype == "float64": return call_pure_extern(op.dtype, op.name, *op.args) return op def _rule_float_direct(op): """Intrinsic rule: Directly call pure extern function for floats. This is an example intrinsic generation rule. Parameters ---------- op : Expr The call expression of original intrinsic. Returns ------- ret : Expr The translated intrinsic rule. Return same op if no translation is possible. See Also -------- register_intrin_rule : The registeration function for intrin rule. """ if str(op.dtype).startswith("float"): return call_pure_extern(op.dtype, op.name, *op.args) return None @_register_func("tvm.default_trace_action") def _tvm_default_trace_action(*args): print(list(args)) def trace(args, trace_action="tvm.default_trace_action"): """Trace tensor data at the runtime. The trace function allows to trace specific tensor at the runtime. The tracing value should come as last argument. The trace action should be specified, by default tvm.default_trace_action is used. Parameters ---------- args : list of Expr or Buffers. Positional arguments. trace_action : str. The name of the trace action. Returns ------- call : Expr The call expression. See Also -------- tvm.call_packed : Creates packed function. """ if not isinstance(args, list): raise Exception("tvm.trace consumes the args as list type") call_args = [_pack_buffer(x) if isinstance(x, _Buffer) else x for x in args] call_args.insert(0, trace_action) return _make.Call( args[-1].dtype, "tvm_call_trace_packed", call_args, _Call.Intrinsic, None, 0) # opencl pattern for exp register_intrin_rule("opencl", "exp", _rule_float_direct, override=True) # default pattern for exp register_intrin_rule("default", "exp", _rule_float_suffix, override=True)